1. Field of the Invention
The present invention relates to a pattern generating apparatus for use in a dot printer, cathode ray tube display, laser beam printer or the like, and more particularly to a pattern generating apparatus capable of providing various forms.
2. Description of the Prior Art
In apparatus for providing character information and form information, there is already known a method of making form lines by connecting form symbols of a same size as that of character symbols.
FIG. 1 shows an example of output of the characters with form lines, in which the form symbols are accessed in the same units as those for the characters A, B, C, . . . , X, Y, Z, a, b, c, . . . , x, y, z to provide continuous form lines.
The form lines in FIG. 1 require 9 form symbols (1) to (9) in FIG. 2, and further complicated form lines require additional 7 form symbols as shown in FIG. 3 (1) to (7).
In general, in order to express two kinds of lines, i.e. blank lines and solid lines in this case, there are required 2.sup.4 form symbols, as represented by the sum of the symbols shown in FIGS. 2 and 3.
In 3-kind representation including thin and thick solid lines, the number of required form symbols increases to 3.sup.4 =81.
In further generalization, a representation involving form lines of N kinds requires N.sup.4 form symbols. For example, a simple output representation involving thin and thick broken lines in addition to the foregoing, thus involving 5 kinds of form line, requires form symbols as many as 5.sup.4 =625, form symbols and an addition of a chain line to this representation raises the number of required form symbols to 1250.
The number of data or character symbols has been made considerably clear due to recent investigations made toward the selection of minimum characters and symbols and the standardization of symbol style.
On the other hand, the number of form symbols, though it may seem relatively limited, becomes very large if increased freedom in form design is desired. In such apparatus the number of form symbols is proportional to the capacity of the form memory in the character generator and is an important factor in the cost and dimension of the entire apparatus.